It's fantastic, I broke down how Durkin is deploying their great talent at SB Nation.
In this breakdown I reveal Manny Diaz's hierarchy of defense. A great defense is established first with culture, secondly with player, and finally with schemes.
If a team doesn't have a culture that creates physical, self-sacrificial players you aren't going to have a great defense. If you don't have some great player, you obviously aren't going to have a great defense. If you have the first two, then at that point good schemes can be brought to bear.
With Harbaugh's football culture, physicality is a given which makes him the rare offensive-minded coach who can expect to see his program consistently play great defense. Normally the ideal pairing is a defensive coach who knows how to hire and support exceptional offensive coaches.